This invention relates generally to handling articles, and especially those for industrial and other uses and particularly fasteners and other articles that are of complex shape and do not flow easily when grouped together in a mass. Threaded fasteners, namely, fasteners having a shaft with an enlarged end or head and a threaded section along the shaft, such as screws and threaded bolts. Such fasteners are used in many fabrication operations in many industries are in this category.
In automatic fastening operations a mass of fasteners, in an appropriate size, is placed in an apparatus, such as a screw feeder, that collates the fasteners and then feeds them consecutively to one or more fastening devices at fastening locations. An additional charge of fasteners is fed to the apparatus each time its supply of fasteners runs out or when all of the fasteners in the machine have been removed for changeover to a different kind or style of fastener. An amount of fasteners is supplied in each charge to meet the capacity of the machine for fasteners without supplying more than the machine can handle.
Fasteners for use in larger quantities, such as in automatic fastening operations, are typically supplied in bulk to users as a jumble of fasteners in a box or other package. Some supply boxes contain a quantity of fasteners appropriate for charging a particular type of'fastener feeder and the box can thus be used to supply the measured amount for charging, as by emptying the contents into the screw feeder by hand. However, in sustained operations, a changeover of fastener types is required periodically. Thus a large unmeasured amount of each fastener type accumulates in a mass that must be portioned out by hand into proper charges and serially fed by hand into the article feeder. Moreover, in either case, feeding the charge by hand is time-consuming, particularly where the article feeder is at an elevated or otherwise difficult location.
Accordingly, it would be desirable to have the mass of screws automatically parceled out or metered into the desired amounts and transported as groups to automatic fastener feeders or other applications. However, industrial fasteners are typically elongate or oblong with enlarged heads or other protuberances, particularly screws with their helical threads. Such fasteners in a mass exhibit a peculiar and unique rheology. In the mass these articles tend to interlock which inhibits flow of the articles. Pressure applied to the mass, indeed even the weight of the screws alone will cause the mass to become cohesive, thus inhibiting flow of and penetration into the mass. Consequently, it can be difficult to pour fasteners from a mass, grab or otherwise extract a desired quantity of fasteners from the mass. This also makes these articles difficult to transport and meter or quantify in bulk such fasters, particularly in an automated approach.
Vacuum devices have been widely used to pick up, transport and deposit a desired sites many kinds of articles, including various types of fasteners, such a blind side fasteners. Typically these devises have a conduit having a mouth or orifice sized to be smaller than articles to be picked up so that the articles do not enter the conduit, itself. For example, as shown in U.S. Pat. No. 6,688,489, each fastener may be separately picked up and transported by a vacuum nozzle. However, these devices are sized to handle only a single fastener and contemplate only picking up and moving a single fastener individually one at a time, the vacuum nozzle attaching to a flat surface of the fastener (the head). The nozzle is designed with an opening smaller than the fastener head so that, when the fastener becomes attached, there ceases to be any vacuum communication with other (adjacent) so that the attached fastener can be isolated and transported on the nozzle by itself. Moreover, the fasteners must be first collated for individual pick up. Thus, this vacuum approach is not suitable for dealing with a mass of uncollated fasteners.
Some conventional vacuum cleaners, such as some shop vacuums, are capable of sweeping up debris, including, dirt and small objects such as bolts, screws and the like, into a tank in which a vacuum is maintained. Such machines typically employ wands that are integral with the machine or attached through a flexible hose to a hand held implement for sweeping surfaces, to scour surfaces and dislodge debris for pick up by the wand mouth of dirt and debris on surfaces (e.g. rugs or floor surfaces) against which such vacuum wands are applied. These wands typically comprise brushes or rotating rug beaters. However, such units have no capability of or purpose for segregating into measured quantities any such sweepings. Nor have these vacuums any capability for depositing such measured quantities at a location exterior to the vacuum tank. Typically these cleaners are for collecting dust, dirt and small particles, rather than substantial quantities of discrete articles. In the case of cleaning the dust from fragile manuscripts it has been recommended to interpose cheesecloth between, the vacuum wand and the sweeping brush to avoid pick up of and injury to the manuscript.
Vibratory processing equipment is utilized widely in industry for a variety of purposes. These include vibratory feeders and particularly vibratory bowl feeders for feeding individual components, including fasteners, Such feeders typically segregate individual components from a mass and convey them along tracks to form a continuous stream of the components that is fed to a downstream location for further processing and utilization. Such feeders would require additional equipment to separate the stream into discrete measured groups of components and would be an inefficient way of segregating and conveying measured groups of components from a mass.